Consumer-Level Food Loss Estimates and Their Use in the ERS Loss-Adjusted Food Availability Data

What Is the Issue?

The Food Availability (per capita) Data System developed by
USDA's Economic Research
Service (ERS) tracks annual food and nutrient availability (a
proxy for consumption) in the
United States since 1909 for several hundred commodities. Because
the core Food Availability
data series in the system overstates actual consumption, ERS has
added another series to the
system-the Loss-Adjusted Food Availability data-which adjusts the
Food Availability data for
nonedible food parts and food losses, including losses from farm
to retail, at retail, and at the
consumer level. This second data series more closely estimates per
capita consumption.

The current Loss-Adjusted Food Availability data are incomplete
and need updating. Under an
agreement with ERS, RTI International has proposed new estimates
for the data series' loss of
the edible share of food at the consumer level. These proposed
estimates cover food loss both
at home and away from home for most of the commodities included in
the series. These losses
include losses during cooking and preparation (e.g., frying fats);
discards due to preparation of
too much food; expired use-by/open dates; spoilage; and plate
waste. ERS then examined how
adoption of RTI's proposed estimates in this data series would
affect ERS's per capita estimates
of daily calories and pounds available for consumption per year
for each commodity. Higher
loss estimates relative to current ERS loss estimates equate to
decreased consumption; lower
estimates equate to increased consumption. The purpose of this
report is to provide documentation about the proposed estimates and
to make these estimates available for public comment. We propose to
adopt the new estimates for the entire data span (1970 to the most
recent year in the series).

What Did the Study Find?

Proposed loss estimates. Consumer-level food
loss varies greatly among individual foods
based on a number of factors, such as a food's perishability or
shelf life, the likelihood of a food
being used as an ingredient or eaten without further preparation,
and the degree to which a
food is typically consumed by children or adults (because of
differences in food consumption
patterns across age groups). Based on RTI's proposed estimates,
foods with the largest annual
increase (more than 35 percentage points) in estimated
consumer-level loss as compared with the currently used ERS
estimates include fresh pumpkin, dry buttermilk, dry whole and
nonfat milk, Swiss cheese, edible beef tallow, and lard. Foods with
the largest decrease (more than 15 percentage points) include
chicken, lamb, nonfat cottage cheese, frozen potatoes, and veal.
Changes in consumer-level food loss estimates could stem from
changes in food preparation habits and the increase in food
consumed away from home or simply from RTI's use of a different
methodology for calculating losses than that used currently by
ERS.

Effects of proposed loss estimates on ERS food
availability estimates. If RTI's proposed food loss
estimates are adopted for use in ERS's data series, changes in
estimates of per capita availability of individual foods relative
to current ERS estimates would vary. Changes over entire food
groups, however, would tend to be small. The most affected group
would be meat, poultry, fish, eggs, and nuts, with an annual
increase in food available for consumption of 22.3 pounds per
person, or 15 percent. The food group with the smallest change
would be grain products, with an annual decrease in availability of
2.1 pounds per person, or 1.5 percent, though RTI could calculate
estimates for only three grain products due to data limitations,
such as when the grain was used almost exclusively as an ingredient
(e.g., various types of flours). Overall, use of RTI's proposed
estimates in the data series would result in a reduction in
estimated per capita availability of 17.3 pounds of food per year,
or 41.9 fewer calories per day, for the average American.

How Was the Study Conducted?

RTI conducted the first of two phases in this study by comparing
estimates of total U.S. retail household purchases with total U.S.
at-home consumption for each food in ERS's Loss-Adjusted Food
Availability series. The main data sources included The Nielsen
Company's Homescan® data for 2004 (food purchases from retail
outlets) and the National Health and Nutrition Examination Survey
(NHANES) for 2003-04 (food consumption). RTI also calculated
alternative estimates of food loss by comparing the total quantity
available at the consumer level in the Loss-Adjusted Food
Availability series with total reported consumption in NHANES. RTI
relied on several supplemental data sources to adjust the purchase
data to facilitate comparisons with the consumption data. In
addition, RTI took direct measurements of count data (e.g., produce
sold by count rather than weight), inedible percentages of food,
and moisture gains for foods if data were not available from one of
the data sources.

RTI also developed and conducted an expert panel to provide
additional data for the analysis, including estimates of food loss
to validate the RTI estimates (or provide an estimate for foods for
which estimates could not be calculated) and estimates of the
percentage of each food typically used as an ingredient. Based on
the resulting data, RTI provided one recommended or proposed
estimate for each food for which an updated estimate could be
calculated for use in ERS' Loss-Adjusted Food Availability
data.

In the second phase of this study, ERS applied the
consumer-level loss estimates proposed by RTI for each commodity to
ERS's Loss-Adjusted Food Availability data. Results revealed
changes in ERS estimates of the pounds of food available for
consumption per capita per year, and changes in the number of
calories available for consumption per capita per day.